AbSciCon19, June 24 by Petar Penev


For me AbSciCon 2019 started with a lot of meetings and short encounters with people I know and have missed seeing in the past year. This transitioned during the sessions into me meeting with several ideas I already knew and quite a few I didn’t. For the first time I started thinking about preservation of biosignatures during David Des Marais` plenary talk.

Somehow in my head there were only preserver jars stored somewhere outside of Earth. So, I allowed myself to reimagine the slide as a preserver jar.

preserver jar

Of course, even if we do have preservation and observation of biosignatures that does not immediately mean there is a biological process causing it. Just last week yet, another transient methane plume was detected on the Mars surface, as reiterated later in the day by Paul Mahaffy, but we are still very far from claiming that there are microbes on Mars.

Creating a statistical framework that would allow us to say how likely is Life on another planet, given some measurements and our understanding of the processes behind the Origin of Life is what brings us together, and all of it should be done under the hat of Bayes’ theorem. My teacher in Bayesian statistics explained applying the frequentist or Bayesian methods like putting on different ‘hats’, underlying the importance of changing our way of thinking. Sarah Walker also did that by proposing using a Bayesian framework to calculate likelihood of each biosignature being generated by Life or non-Life.


As noted by a question from the audience one of the biggest challenges in using a Bayesian method would be calculating the prior probability of Life’s existence. We have just a single observation of a living planetary systems and we cannot see it the same way we see other planets, since we are living on it. At the same time our studies of the ways life can emerge and evolve complexity are far from concluded.

All this underlines the importance of the entire astrobiological community working together and sharing their results and ideas to reach a better understanding of what we want to see, how we can look at it, and what does seeing it means. With that I would like to share the SAGANet stand that allows all AbSciCon attendees to draw their science, together on one canvas.